Stihl 45 C Owners Manual

							{
STIHL HS 45
WARNING
Read Instruction Manual thoroughly 
before use and follow all safety 
precautions – improper use can 
cause serious or fatal injury.
ADVERTENCIA
Antes de usar la máquina lea y siga 
todas las precauciones de 
seguridad dadas en el manual de 
instrucciones – el uso incorrecto 
puede causar lesiones graves o 
mortales.
,QVWUXFWLRQ0DQXDO
0DQXDOGHLQVWUXFFLRQHV 
						

							Instruction Manual
1 - 32
Manual de instrucciones
33 - 69 
						

							Original Instruction Manual Printed on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled. © ANDREAS STIHL AG & Co. KG, 2017
0458-253-8621-B. VA1.A17. 
0000006579_009_GB
HS 45
English
1
{This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process 
with electronic systems.
Contents
Allow only persons who fully understand 
this manual to operate your hedge 
trimmer.
To receive maximum performance and 
satisfaction from your STIHL hedge 
trimmer, it is important that you read, 
understand and follow the safety 
precautions and the operating and 
maintenance instructions in chapter 
"Safety Precautions and Working 
Techniques" before using your hedge 
trimmer. For further information you can 
go to www.stihlusa.com.
Contact your STIHL dealer or the STIHL 
distributor for your area if you do not 
understand any of the instructions in this 
manual.
WARNING
Because a hedge trimmer is a high-
speed cutting tool some special safety 
precautions must be observed to reduce 
the risk of personal injury. Careless or 
improper use may cause serious or even 
fatal injury. Guide to Using this Manual 2
Safety Precautions and Working 
Techniques 3
Using the Unit 12
Fuel 13
Fueling 14
Starting / Stopping the Engine 14
Operating Instructions 16
Cleaning the Air Filter 16
Engine Management 17
Adjusting the Carburetor 17
Spark Plug 18
Engine Running Behavior 20
Lubricating the Gearbox 20
Storing the Machine 21
Sharpening Instructions 21
Inspections and Maintenance by 
Dealer 21
Maintenance and Care 22
Main Parts 24
Specifications 25
Maintenance and Repairs 26
Disposal 26
Limited Warranty 27
STIHL Incorporated Federal 
Emission Control Warranty 
Statement 27
STIHL Incorporated California 
Exhaust and Evaporative 
Emissions Control Warranty 
Statement 29
Trademarks 31 
						

							HS 45
English
2
Pictograms
The meanings of the pictograms 
attached to or embossed on the 
machine are explained in this manual.
Depending on the model concerned, the 
following pictograms may be on your 
machine.
Symbols in Text
Many operating and safety instructions 
are supported by illustrations.
The individual steps or procedures 
described in the manual may be marked 
in different ways:
NA bullet marks a step or procedure.A description of a step or procedure that 
refers directly to an illustration may 
contain item numbers that appear in the 
illustration. Example:
NLoosen the screw (1).
NLever (2) ...
In addition to the operating instructions, 
this manual may contain paragraphs 
that require your special attention. Such 
paragraphs are marked with the 
symbols and signal words described 
below:
DANGER
Indicates a hazardous situation that, if 
not avoided, will result in death or 
serious injury.
WARNING
Indicates a hazardous situation that, if 
not avoided, could result in death or 
serious injury.
NOTICE
Indicates a risk of property damage, 
including damage to the machine or its 
individual components.
Engineering Improvements
STIHL’s philosophy is to continually 
improve all of its products. As a result, 
engineering changes and improvements 
are made from time to time. Therefore, 
some changes, modifications and 
improvements may not be covered in 
this manual. If the operating 
characteristics or the appearance of 
your machine differs from those described in this manual, please contact 
your STIHL dealer or the STIHL 
distributor for your area for assistance.
Guide to Using this Manual
Fuel tank for gasoline 
and engine oil mixture
Press to operate manual 
fuel pump
Filler hole for gear 
lubricant
Starting lock
Rotating rear handle 
						

							HS 45
English
3 Have your STIHL dealer show you how 
to operate your power tool. Observe all 
applicable local safety regulations, 
standards and ordinances.
WARNING
Do not lend or rent your power tool 
without the instruction manual. Be sure 
that anyone using it understands the 
information contained in this manual.
WARNING
The use of this machine may be 
hazardous. If the cutting tool comes in 
contact with your body, it will cut you.
Use your hedge trimmer only for cutting 
hedges, shrubs, scrub, bushes and 
similar material.
WARNING
Do not use it for other purposes, since 
misuse may result in personal injury or 
property damage, including damage to 
the machine.
WARNING
Minors should never be allowed to use 
this power tool. Bystanders, especially 
children, and animals should not be 
allowed in the area where it is in use.
WARNING
To reduce the risk of injury to bystanders 
and damage to property, never let your 
power tool run unattended. When it is 
not in use (e.g. during a work break), 
shut it off and make sure that 
unauthorized persons do not use it.
Most of these safety precautions and 
warnings apply to the use of all STIHL 
hedge trimmers. Different models may 
have different parts and controls. See 
the appropriate section of your 
instruction manual for a description of 
the controls and the function of the parts 
of your model.
Safe use of a hedge trimmer involves
1.the operator
2.the power tool
3.the use of the power tool.
THE OPERATOR
Physical Condition
You must be in good physical condition 
and mental health and not under the 
influence of any substance (drugs, 
alcohol, etc.) which might impair vision, 
dexterity or judgment. Do not operate 
this machine when you are fatigued.
WARNING
Be alert – if you get tired, take a break. 
Tiredness may result in loss of control. 
Working with any power tool can be 
strenuous. If you have any condition that 
might be aggravated by strenuous work, 
check with your doctor before operating 
this machine.
WARNING
Prolonged use of a power tool (or other 
machines) exposing the operator to 
vibrations may produce whitefinger 
disease (Raynaud's phenomenon) or 
carpal tunnel syndrome.
These conditions reduce the hand's 
ability to feel and regulate temperature, 
produce numbness and burning 
sensations and may cause nerve and 
circulation damage and tissue necrosis.
All factors which contribute to 
whitefinger disease are not known, but 
cold weather, smoking and diseases or 
physical conditions that affect blood 
vessels and blood transport, as well as 
high vibration levels and long periods of 
Safety Precautions and 
Working Techniques
Because a hedge trim-
mer is a high-speed, fast-
cutting power tool with 
sharp cutting blades, 
special safety precau-
tions must be observed to 
reduce the risk of per-
sonal injury.
It is important that you 
read, fully understand 
and observe the following 
safety precautions and 
warnings. Read the 
instruction manual and 
the safety precautions 
periodically. Careless or 
improper use may cause 
serious or fatal injury. 
						

							HS 45
English
4 exposure to vibration are mentioned as 
factors in the development of whitefinger 
disease. In order to reduce the risk of 
whitefinger disease and carpal tunnel 
syndrome, please note the following:
–Most STIHL power tools are 
available with an anti-vibration 
("AV") system designed to reduce 
the transmission of vibrations 
created by the machine to the 
operator's hands. An AV system is 
recommended for those persons 
using power tools on a regular or 
sustained basis.
–Wear gloves and keep your hands 
warm.
–Keep the AV system well 
maintained. A power tool with loose 
components or with damaged or 
worn AV elements will tend to have 
higher vibration levels.
–Maintain a firm grip at all times, but 
do not squeeze the handles with 
constant, excessive pressure. Take 
frequent breaks.
All the above-mentioned precautions do 
not guarantee that you will not sustain 
whitefinger disease or carpal tunnel 
syndrome. Therefore, continual and 
regular users should closely monitor the 
condition of their hands and fingers. If 
any of the above symptoms appear, 
seek medical advice immediately.
WARNING
The ignition system of the STIHL unit 
produces an electromagnetic field of a 
very low intensity. This field may 
interfere with some pacemakers. To 
reduce the risk of serious or fatal injury, 
persons with a pacemaker should consult their physician and the 
pacemaker manufacturer before 
operating this tool.
Proper Clothing
WARNING
To reduce the risk of injury, the operator 
should wear proper protective apparel.
WARNING
Be particularly alert and cautious when 
wearing hearing protection because 
your ability to hear warnings (shouts, 
alarms, etc.) is restricted.Avoid loose-fitting jackets, scarfs, 
neckties, jewelry, flared or cuffed pants, 
unconfined long hair or anything that 
could become caught on branches, 
brush or the moving parts of the unit. 
Secure hair so it is above shoulder level.
THE POWER TOOL
For illustrations and definitions of the 
power tool parts see the chapter on 
"Main Parts".
WARNING
Never modify this power tool in any way. 
Only attachments supplied by STIHL or 
expressly approved by STIHL for use  To reduce the risk of 
injury to your eyes never 
operate your power tool 
unless wearing goggles 
or properly fitted protec-
tive glasses with 
adequate top and side 
protection complying with 
ANSI Z87 "+" (or your 
applicable national stand-
ard.) To reduce the risk of 
injury to your face STIHL 
recommends that you 
also wear a face shield or 
face screen over your 
goggles or protective 
glasses.
Power tool noise may 
damage your hearing. 
Wear sound barriers (ear 
plugs or ear mufflers) to 
protect your hearing. 
Continual and regular 
users should have their 
hearing checked 
regularly.
Always wear heavy duty 
work gloves (e.g. made of 
leather or other wear 
resistant material) when 
handling the machine 
and the cutting tool. 
Heavy-duty, nonslip 
gloves improve your grip 
and help to protect your 
hands.
Clothing must be sturdy 
and snug-fitting, but allow 
complete freedom of 
movement. Wear long 
pants made of heavy 
material to help protect 
your legs. Do not wear 
shorts, sandals or go 
barefoot.
Good footing is very 
important. Wear sturdy 
boots with nonslip soles. 
Steel-toed safety boots 
are recommended. 
						

							HS 45
English
5 with the specific STIHL model are 
authorized. Although certain 
unauthorized attachments are useable 
with STIHL power tools, their use may, 
in fact, be extremely dangerous.
If this tool is subjected to unusually high 
loads for which it was not designed (e.g. 
heavy impact or a fall), always check 
that it is in good condition before 
continuing work. Check in particular that 
the fuel system is tight (no leaks) and 
that the controls and safety devices are 
working properly. Do not continue 
operating this machine if it is damaged. 
In case of doubt, have it checked by your 
STIHL servicing dealer.
THE USE OF THE POWER TOOL
Transporting the Power Tool
WARNING
To reduce the risk of injury from blade 
contact, never carry or transport your 
power tool with the cutter blades 
moving.It may be carried only in the horizontal 
position. Grip the front handle and keep 
the hot muffler away from your body and 
the cutter blades behind you.
WARNING
Always switch off the engine and fit the 
scabbard over the cutter blades before 
transporting the power tool over long 
distances. When transporting it in a 
vehicle, properly secure it to prevent 
turnover, fuel spillage and damage to 
the unit.
Fuel
Your STIHL power tool uses an oil- 
gasoline mixture for fuel (see the 
chapter on "Fuel" of your instruction 
manual.)
WARNING
Fueling Instructions
WARNING
Fuel your power tool in well-ventilated 
areas, outdoors. Always shut off the 
engine and allow it to cool before 
refueling. Gasoline vapor pressure may 
build up inside the fuel tank depending 
on the fuel used, the weather conditions 
and the tank venting system.
In order to reduce the risk of burns and 
other personal injury from escaping gas 
vapor and fumes, remove the fuel filler 
cap on your power tool carefully so as to 
allow any pressure build-up in the tank 
t o  r e l e a s e  s l o w l y .  N e v e r  r e m o v e  t h e  f u e l  
filler cap while the engine is running.
Gasoline is an extremely 
flammable fuel. If spilled 
and ignited by a spark or 
other ignition source, it 
can cause fire and seri-
ous burn injury or 
property damage. Use 
extreme caution when 
handling gasoline or fuel 
mix. Do not smoke or 
bring any fire or flame 
near the fuel or the power 
tool. Note that combus-
tible fuel vapor may 
escape from the fuel 
system. 
						

							HS 45
English
6 Flip up the lever and slowly turn left (1) 
to the vent position of the cap at about 
1/8 turn where the cap is held in place by 
the thread. Once the fumes have been 
relieved, turn (2) the cap further to the 
1/4 turn position where the tool-less cap 
can be removed from the tank thread.
Never remove the fuel filler cap by 
quickly turning it to the full 1/4 open 
position without letting it vent out any 
vapor/pressure build-up at the 
1/8 position.
Select bare ground for fueling and move 
at least 10 feet (3 m) from the fueling 
spot before starting the engine. Wipe off 
any spilled fuel before starting your 
machine.
WARNING
WARNING
In order to reduce the risk of fuel spillage 
and fire from an improperly tightened 
fuel cap, correctly position and tighten 
the fuel cap in the fuel tank opening.
Different models may be equipped with 
different fuel caps.
Toolless cap with grip
To do this with this STIHL cap, raise the 
grip on the top of the cap until it is upright 
at a 90° angle. Insert the cap in the fuel 
tank opening with the raised positioning 
marks on the grip of the cap and on the 
fuel tank opening lining up. Using the 
grip, press the cap down firmly while 
turning it clockwise as far as it will go 
(approx. 1/4 turn).Misaligned, damaged or broken cap
NIf the cap does not drop fully into the 
opening when the positioning marks 
line up and/or if the cap does not 
tighten properly when twisted, the 
base of the cap may be prematurely 
rotated (in relation to the top) to the 
closed position. Such misalignment 
can result from handling, cleaning 
or an improper attempt at 
tightening.
Check for fuel leakage 
while refueling and during 
operation. If fuel leakage 
is found, do not start or 
run the engine until the 
leak is fixed and any 
spilled fuel has been 
wiped away. Take care 
not to get fuel on your 
clothing. If this happens, 
change your clothing 
immediately.
2
0000-GXX-0908-A0
1
001BA220 KN
)ROGWKHJULSIOXVKZLWK
WKHWRSRIWKHFDS*ULS
WKHFDSDQGFKHFNIRU
WLJKWQHVV,IWKHJULSGRHV
QRWOLHFRPSOHWHO\IOXVK
ZLWKWKHFDSDQGWKH
GHWHQWRQWKHJULSGRHV
QRWILWLQWKHFRUUHVSRQG-
ing recess in the filler 
opening, or if the cap is 
loose in the filler opening, 
the cap is not properly 
seated and tightened and 
you must repeat the 
above steps.
Left: Base of cap in closed posi-
tion (with open space)
Right: Base of cap correctly posi-
tioned for installation
001BA227 KN 
						

							HS 45
English
7 NTo return the cap to the open 
position for installation, turn the cap 
(with the grip up) until it drops fully 
into the tank opening. Next, twist the 
cap counterclockwise as far as it will 
go (approx. 1/4 turn) – this will twist 
the base of the cap into the correct 
position. Then, twist the cap 
clockwise, closing it normally.
NIf your cap still does not tighten 
properly, it may be damaged or 
broken; immediately stop use of the 
unit and take it to your authorized 
STIHL dealer for repair.
Screw Cap
WARNING
See also the "Fueling" chapter in your 
Instruction Manual for additional 
information.Before Starting
WARNING
Always check your power tool for proper 
condition and operation before starting, 
particularly the throttle trigger, throttle 
trigger lockout, stop switch and cutting 
tool. The throttle trigger (if applicable) 
must move freely and always spring 
back to the idle position. Never attempt 
to modify the controls or safety devices.
WARNING
Check fuel system for leaks, especially 
the visible parts, e.g., filler cap, hose 
connections, manual fuel pump (only for 
power tools equipped with a manual fuel 
pump). Do not start the engine if there 
are leaks or damage – risk of fire! Have 
the machine repaired by a servicing 
dealer before using it.
WARNING
Never use a power tool that is damaged 
or not properly maintained.
WARNING
Check that the spark plug boot is 
securely mounted on the spark plug – a 
loose boot may cause arcing that could 
ignite combustible fumes and cause a 
fire.
Keep the handles clean and dry at all 
times; it is particularly important to keep 
them free of moisture, pitch, oil, fuel mix, 
grease or resin in order for you to 
maintain a firm grip and properly control 
your power tool.
WARNING
The cutting tool must be properly 
tightened and in safe operating 
condition. Inspect for loose parts (nuts, 
screws, etc.) and for cracked, bent, 
warped or damaged blades. Regularly 
check the condition and tightness of the 
cutter blades – with the engine stopped! 
Replace damaged cutter blades before 
using the power tool. Always keep 
blades sharp.
STIHL recommends that you always 
spray the cutter blades with STIHL resin 
solvent before starting work – with the 
engine stopped! You can obtain this 
protective spray from your dealer. Apply 
generously.
Starting
Start the engine at least 10 feet (3 m) 
from the fueling spot, outdoors only.
For specific starting instructions, see the 
appropriate section of your manual. 
Place the power tool on firm ground or 
other solid surface in an open area. 
Maintain good balance and secure 
footing.
WARNING
To reduce the risk of injury from blade 
contact, be absolutely sure that the 
cutting tool is clear of you and all other 
obstructions and objects, including the 
ground, because when the engine starts 
at starting-throttle, engine speed will be 
fast enough for the clutch to engage and 
move the blades on the cutting tool. Unit vibrations can cause 
an improperly tightened 
fuel filler cap to loosen or 
come off and spill quanti-
ties of fuel. In order to 
reduce the risk of fuel 
spillage and fire, tighten 
the fuel filler cap by hand 
as securely as possible.
001BA226 KN 
						

							HS 45
English
8 Once the engine has started, 
immediately blip the throttle trigger, 
which should release the starting throttle 
and allow the engine to slow down to 
idle.
WARNING
Your power tool is a one-person 
machine. Do not allow other persons in 
the general work area, even when 
starting.
WARNING
To reduce the risk of injury from loss of 
control, do not attempt to "drop start" 
your power tool.
WARNING
When you pull the starter grip, do not 
wrap the starter rope around your hand. 
Do not let the grip snap back, but guide 
the starter rope to rewind it properly. 
Failure to follow this procedure may 
result in injury to your hand or fingers 
and may damage the starter 
mechanism.
Important Adjustments
WARNING
To reduce the risk of personal injury 
from loss of control or contact with the 
running cutting tool, do not use your unit 
with incorrect idle adjustment. At correct 
idle speed, the cutting tool should not 
move. For directions on how to adjust 
idle speed, see the appropriate section 
of your instruction manual.If you cannot set the correct idle speed, 
have your STIHL dealer check your 
power tool and make proper 
adjustments and repairs.
During Operation
Holding and Controlling the Power Tool
Always hold the unit firmly with both 
hands on the handles while you are 
working. Wrap your fingers and thumbs 
around the handles.
Right-hand Use
Put your right hand on the rear handle, 
left hand on the front handle.
Operate the machine so that the cutting 
blades are always away from your body.
Left-hand Use
Put your left hand on the rear handle, 
right hand on the front handle.
WARNING
WARNING
Do not overreach. Keep proper footing 
and balance at all times. Special care 
must be taken in slippery conditions (wet 
ground, snow) and in difficult, overgrown 
terrain. Watch for hidden obstacles such 
as tree stumps, roots and ditches to 
avoid stumbling. For better footing, clear 
away fallen branches, scrub and 
cuttings. Be extremely cautious when 
working on slopes or uneven ground.
WARNING
To reduce the risk of injury from loss of 
control, never work on a ladder, in a tree 
or any other insecure support. Never 
hold the machine above shoulder 
height.
Working Conditions
Operate and start your power tool only 
outdoors in a well ventilated area. 
Operate it under good visibility and 
daylight conditions only. Work carefully.
Never attempt to operate 
your power tool with one 
hand. Loss of control of 
the power tool resulting in 
serious or fatal injury may 
result. To reduce the risk 
of cut injuries, keep 
hands and feet away 
from the cutting tool. 
Never touch a moving 
cutting tool with your 
hand or any other part of 
your body.